Üç farklı pestisitin (klorifos-etil, 2,4-diklorofenoksiasetik asit, metalaksil-m + mankozep) zebra cikletlerinin (amatitlania nigrofasciata)oksijen tüketim oranları ve davranışsal tepkileri üzerindeki etkileri

Pesticides are very toxic for fresh water ecosystem and generally derived from agricultural process for controlling pests, broadleaf plants and fungus to inhibit yield losses, protect crops, improve crop quality, simplify harvesting and reduce expenditure. Chlorpyriphos-Ethyl (CF-E), 2,4-Dichlorophenoxyacetic acid (2,4-D) and Metalaxyl-M+Mancozeb (MMM) mixture are the most widely used as insecticides, herbicide and fungicide, respectively, in Bolu region. In this study, male zebra cichlids (Amatitlania nigrofasciata) were exposed sublethal concentration of these three pesticides. Oxygen consumption rates and behavioral responses were determined under five different sublethal concentrations of three pesticides (CF-E; 0, 0.004, 0.008, 0.016, 0.032, 0.05 mg/l, 2,4-D; 0, 2.17, 4.35, 8.69, 17.38, 28.97 mg/l and MMM; 0, 0.16, 0.32, 0.64, 1.0, 1.6 mg/l) in similar weight of male zebra cichlids at 24±1°C for 96h. After the measurement of oxygen consumption rates by intermittent flow through computer controlled respirometry, routine metabolic rate and standard metabolic rate were calculated by statistical analysis. During the experimental period, oxygen consumption rates from three pesticides increased linearly as their concentration increased from 0.004 to 0.032 mg/l in CF-E, 2.17 to 17.38 mg/l in 2,4-D and 0.16 to 1.0 mg/l in MMM. Oxygen consumption rates decreased after at 0.032 mg/l in CF-E, 17.38 mg/l in 2,4-D and 1.0 mg/l in MMM. Cichlid fish exposed to pesticides showed abnormal behavioral activity such as, hyperexcitation, loss of equilibrium, irregular swimming, change in body color and finally sinking at the corner of test tank and staying motionless in there. Along the experiment, severe respiratory stress, rapid opercular activity, excessive mucus secretion and fatigue were also observed in the zebra cichlid. Keywords: pesticides; toxicity; respirometry; oxygen consumption; behavioral dysfunction; zebra cichlid